HashMap的兩種周遊方式

package hashmap周遊;

import java.util.HashMap;
import java.util.Map.Entry;
import java.util.Set;

public class Demo {

	public static void main(String[] args) {

		HashMap<String, String> hashMap = new HashMap<String, String>();
		hashMap.put("a", "1");
		hashMap.put("b", "2");
		hashMap.put("c", "3");
		hashMap.put("d", "4");

		System.out.println("第一種周遊");
		Set<String> keySet = hashMap.keySet();
		for (String key : keySet) {
			String value = hashMap.get(key);
			System.out.println("key是" + key + "---value是" + value);
		}
		
		System.out.println("第二種周遊");
		Set<Entry<String,String>> entrySet = hashMap.entrySet();
		for (Entry<String, String> entry : entrySet) {
			String value = entry.getValue();
			String key = entry.getKey();
			System.out.println("key是" + key + "---value是" + value);
		}
	}
}